Automatically Bring up an Ethernet Interface at Boot Without IP Address

In order to bring up Ethernet interface "eth1" at boot without IP address, add the following section to the file "/etc/network/interfaces":

auto eth1
iface eth1 inet manual
up ifconfig eth1 up

This tells the system to configure the interface (i.e. eth1) manually. The last line tells the system on bringing the interface up, use the command "ifconfig eth1 up".